Ellagic acid, a phenolic compound from the family of Ellagitannins, is naturally found in high concentrations in raspberries, strawberries, and walnuts. For the last 20 years ellagic acid and other ellagitannins have been shown to be effective chemopreventive agents in animal and cell models. The long term goal and objective of this study is to determine if the ellagitannins present in food sources can prevent cancer in humans. Before this can be done, the pharmacokinetic properties of the ellagic acid and the ellagitannins from food sources must be assessd. In the current study volunteers (12) will consume samples of raspberries, strawberries, and walnuts containing similar amounts of ellagitannins. Comparison of the serum and urine levels of ellagitannins will show which food provides the highest concentration of these compounds and is most suited for further study in human chemoprevention clinical trials.